Telegraph switching system



3 Sheets-Sheet 1 W. B.`BLANTON ET AL TELEGRAPH SWITCHING SYSTEM June 27, 1950 Fi'ld Jan. 20, 1945 l l l l l 1|.. mgm

3 Sheets-Sheet ATTORNEY ill. .|.m .oC o. .|.|.|||.l|.1|.||||i|l ..O.-.. w U D aom omen/ lm/X TW ON om wm m uw 1/0 mm E BA w V u u N BJ m l wm n n n .Hu WE m-nz .m omzzoom n lo v mm v u l Il l wv r 2 n n j a.; o v u n w f 1MP u |m/s O ...Sum om. .zou A MN (l HT 1. n E n NIM June 27, 1950 w. B. BLANTON ETAL TELEGRAPH SWITCHING SYSTEM Filed Jan. 2o, 1945 TLV 1t,

June 27, 1950 w. B. BLANToN ET A1. 2,512,605

TELEGRAPH SWITCHING SYSTEM Filed Jan. 20, 1945 3 Sheets-Sheet 3 lllllulllllllllllll|||||l| Patented 'J une 27, 1950 2,512,605; TEnEGRAPHfsWITCHiNG snis'rEMi w'iiiam B. naman, rtbtkviiiecerifre ein* iiawajian mpAgrw, Brckiyn, N. y., 'as 'gpm :1mi/'rhs'. Western Union Telegraph Y(lflnjlzian'y;"ltieiv'York',

NrYaj afc'oriml'ationoinNeWiYbrkl Applicati'onrJanuary 20, 1945,?SerialfNov573J50- 12 "Claims 1st i Thislfinvention relateskto telegraph switching systernsfand `'more 'patic'ulafrlyfto so-'calledl't'el'e-l grarhreperforawr swamps @sensed aptaratus3V wherein reperfbrating equipment isV ern"- ployed tov store signalsiri an storage medium such asafftape which is subseguentl`y'employedf to'cntrol-a tape transmitter to 'eife'ct transmission of the. stored signals toV a-A sending circuit. A

l -A,feature of the invention-resides inthep'rovision of means whereby a single transmitter normally eiective to transmit .signals Istored iantroiaepe, @wir 'snede"activerende timed to effect-irensmissieesf the Signals Stored inits ,tape toa pluralityof circuits.

Another. feature estrie iiiyejritibntresiies in: the ltir.alternent- Whereby a memellylpperebl?, meansfrio'r'mallyA operativehto condition a single transmitter vfor transmission ofthe saine message toi.y a, pluralityof-'vcircuits may be'farra ed tov condition the. transmission 'offtie 'message'to less-thariftherv'total numberL of said `'plurality.r ofY circuits,y Inthis 'connectienafflirther featureV ofthe inventionresides fin; the provisin of 'means to connect groups qf sending circuitstc') the'.

systernfor-transmission kof the single' message .A- further `feature gf .the invention. is the 1arrang'ementvwhereby the individual signal iinpulses ofY code groups fofr 'a messageV are` trans-v miad'sw gseietedones vtif @transformants independentlywithin aprecietermined time in-l In ter-val:` but not necessarily K simultaneously. A this connection another feature is thearra'ngementv whereby the transmission ofA a 'second code group'offimpulses to a plurality. ofQsendingvcircuits isfnotfinitiated until tl'ie completion ofV the. in-

dependent vtr'an'smissio'ri of vtheV precedinglA lcodelAnotlzier 'featureot the invention is the provisioni*of-means-,whereby certain v,types of failure ofqalsig'nal responsive means at uthe receiving endfforfeanyonecr more fof the connected circuits which `is:normally'eiective tofstop further transmission-thereto conditions the system-to continue transmission tothe other. ones oi' the vconnected circuits.:

tion Willfbe more fapparentin the followingA d etailed description of a preferred embodiment thereofshown vin the accompanying drawings.

wherein:4 l I A v e d Figs. 1, 2 and 3, taken together, illustrate dia gramnatically the invention as it maybe applied. to \a. reperforator switching system.

The invention 1S-shew and desiitibei ,:herei1 as itmayybe applied toa reperforator switching (C1: 'ris-ssii c t`ransrniti'fe'rs` such I as, forv example, 1 those e' vrepaeapte 'tov transmit to `a' 'piijraiity of', circuits 15 termed endingrv cicuits `|Refe L l controlled transmitt l, I Zand "l 3 'are )shown witri'as's A iated'ordcircuit's A; 'D Aand H which terminate in pligs -Pt' The "pm x n serted inany one of a nurnbrofassociatedijacks such as` J, `only 'one'of which 'is'fshwn 'associated withi each p1ug,j in' theini'annen'fulliyfset forth" in effect transmission o'f i representative :"signals' to sendingeircits: The reperiora'torsljl'l with theirl associatedtapes l'iian'd 'tranfsrr'iitters constitute` in eiect"'relaying means` whereby" a' pluralityn of Sending circuit,

Printereperfdratos"'seh "as ".21v of the well known 'itypajone offwhcnisassociatedfwith 'each cord circuit; prepare 'tapes 22 in accordance with received 's nalswhich airejemployedt control ass-beratertransmitters as- |2`A andy la Theattendant on rioting vthe destination of the" message" appearing tire tape inserts the ast'ed plug' Pl'in the"`appropriate` jack' J where'- transmissfioirof suc'hamessage is begun' s'sagewan'd a 'transmitter adapted to earsaraera 'rrr-trie drt-winggtiie transmitter n is the @entente n the nazi# ner set forth here nafter, it mavrvble arranged to o resented' Hy the 'rfeerence numeral 'TTT associated -P, ,'1,J thesadf patent 'myfk a plura 1 yfojf jacks J' toa corre#y fana pluralitv ffdiierent 'destinations' is called transinit'v to a plurality or circuits," -i-tthrough-ftsl manner, that is, when a transmitter such as II is transmitting through its cord circuit and plug P to only one selected jack J, relays 20, v23, 24, 25, 26 and 30 of the present drawings functionally operate in substantially the same manner as relays 82, 121, 122, 123, 8l and '76, respectively, of Fig. 2 of the above-mentioned Blanton patent. During these times the character representing code groups from the transmitter in conjunction with an impulse unit such as 21 in the connected jack circuit, control the reperforator I4 to perforate a tape I9 which subsequently is employed to control a transmitter to eiect transmission'of` the stored signals to a remote office. The cord circuit shown in the accompanying drawings include a tape tie-up relay 28 which is'adapted to be operated on the failure of the tape I9 to properly feed through the reperforator I4. The circuit to the tape tie-up relay 28 of each cord circuit may be controlled from a pair of contacts such as 141, Fig. 14, of a patent to R. Hoover, No. 2,252,852, granted August 19, 1941, which patent also discloses a reperforator which may be employed as the reperforator represented by reference numeral I4 herein. DuringV these normal periods of operation of the cord circuits the above-mentioned control circuits,y one for each cord circuit, are unoperative and have no effect over their associated cord circuits.

' The control circuits are arranged to be associated with their cord circuits to operate in conjunction therewith through the operation of a multi-contact manual switch represented gen-` erally b'y reference numeral 29. The switch 29 is divided into two parts 29a and 29h and by operating the first or upper part 29a which includesv that part rof the switch shown in' Figs. 1 and 2 from its normal or regular position, such as that shown in the drawings, to its book posi?- tion where the switch arms will contact the lower one of their two associated contacts, circuits are established whereby the book transmiter I I is conditioned to transmit to a rst group of cord circuits and sending circuits to which their plugs may be connected. By throwing the second or lower part 29h, Fig. 3, of the switch 29 to itsbook position, another group of cord circuits are conditioned to have 'signals from the book transmitter II transmitted therethrough. In the embodiment of the invention shown in the drawings the rst and second parts 29a and 29h respectively of switch 29 control four cord circuits .each and by throwing the rst part 29a, of switch 29 to its book position, signals from thransmitter 'I I may be transmitted through three other cord circuits in addition to its associated cord circuit A. The operation of the lower part 29h of switch 29 from its regular to its book position connects four more cord circuits to the book transmitter II. Each control circuit for a cord circuit has a socalled cut-out switch whereby any oneof the cord circuits connected to the book transmitter II through operation of switch 29 may be eectively disconnected,,therefromy so that, signals ftransmitted from the book transmitter will not be 4 extended through the cord circuits associated with operated cut-out keys.

The impulse unit 21 of a jack circuit in addition to pulsing the intelligence impulses from the transmitter, such as II, of a connected cord circuit, such as A, generates the so-called step pulse which eiects periodic energization of the step magnet 3l of the transmitter to effect advancement of the tape in conjunction with each code group of impulses transmitted. As described and shown in the Blanton patent, the step pulse after passing through contacts of certain relays in the cord circuit, normally divides and passes through both coils of an auto-control relay and thence through parallel paths to the step magnet SM. One of the parallel paths has therein a set of tape lever contacts which open on taut tape to lock up the transmitter. The same general arrangement is employed in the cord circuits in the, accompanying drawings and the step pulse, withthe switch 29 in its regular position, also passes through Various switch arms or the upper 29a, ofswitch 29.

transmitter I I. I advancement of the tape through the transmitter I I with the switch 29 in its regular positionis in all substantial respects similar to thatdescribed inthe Blanton. patentwith reference to riga.`

With the upper "part 29a'of switch 29 inits regular position, the individual circuits Afrom the tongues of the transmitter I I extend through the switch 29 to front contacts of a relay 23,-and with relayn23 energized, these individual circuits are extended to they plug P. When the upper part 29a of switch 29 is thrown to its bookposition,

the tongues of transmitter II are' extended overY individual circuitsto front contacts of relays 33 in each of the control circuits such as V'A to front contacts of relays 423 of respective cord cir-` cuits. Assume that a message appears in tape 22 associated with the fbook transmitter lI I, that is -destined for a number-lof different destinations.`

If, for example, the f book messageis to be trans#y mitted over six different sending circuits,'the opu erator will move both parts12'9d and 29h of the switch `29 from regular'gtojfbook position whereas if the-message is tobetransmittd over four circuits, only one part of the switch,` the upper part 28a, need be moved.' Slinceiitfis as.,

sumed `the book message is tobe transmittedto six circuits, the operator after throwing theupper' and lower sections29a and 29h ofthe switlclr29 to their booky position will operate cut-out switches, such as 34, of two control circuits `and` then insert the plugs P of the cord circuits associated with unoperated cut-out switch into jacks, such as J, assigned to thel desired outgoing cir- A relay 39 isv included in each''cord circuit and operates inthe manner set Aforth in the Blanton patent when its associated plug, such as P, is inserted in a jack J. Ii. it is asumedv that theasso: ciated cord circuit is idle at thetime of the plugging operation, the energization ofi-relay 37as'a result of the pluggingjoper'ation, completes an 0b'- vious c ircuit throughav back Contact of relay 26,

a front contact of relay '30 and'aback contact O Thetape lever contacts 32,` when opened by taut tape, flock up" associated Accordingly the control'of the' Si?. relay'ifor the' illumination nfiaflamp .135; lf'l'lfie illuminationof ithisxlamplindicatestothe opera-l tor'thattheassociatedzcordfcircuit is in condition' forfoper'ati'onfand: itiwillremainilluminated until tlierconnecteiify .'j ack .circuit .is seized fby the. :opera-1^y tion ci relay :262. vLamp .36.is calledrra.l standby.

lamp. f l

4`If the-six `plugs P are plugged up :to idle-jack circuits, allcstandbylampsS :inthe associated cord'-fcircuits..wil1 @beiy illuminated and'ias theseize relays 26 operateftheseelanrps Will 1go out. 'lihe op'er-ati'onfo`f ar seize .relay .mayibe delayed zbecause ofthelassociated cord circuit 'being pluggediup ,to absy ljack"circuitrsinceithe-j acks .J may be mul-l tipledito 'la f pluralityiof positions. When *all ther standby lamps: 36 associated :with thefplugged .up

cord I.circuits rare f extinguished,- the operator'pmomentarily .operates the start lreyi3z54 and inffthe mannerf setiforth lhereinafter.v transmission .ofthe message inithe .tapeof the book transmitter 'III to theplurality of sendingcircuits begins.

rRelays 20 and 25 operate when asendirrg circuit is seized 'and the operation of a relay 230i a cord circuit applies a ground througha contact offy switch 29, they closed contacts 31 of cut-out key 34 of .the associated control circuit, .the right hand tongue and back contact of. a relay f38and through the coil ofa relay V39 tothe positive potential, thusr effecting .energization of relay 39. In the same lmannen-relays 39 of the other control circuitsassociatedwith unoperated cut-out keys .3l are lenergized as the :sending circuits to whichassociated cord circuits-are 'plugged become'idle. AThe energization'of a'relay 33 completes a circuit for the step pulse from a front contact of relay23 of the associated cord circuit, through the right hand .coil of relay25, a make contact and tongue of relay 2t, a back contact andtongue of relay 28, a switch arm and contact of switch 2t, the first left hand tongue and front contact of relay 33., the tongue and back contact of relay El the back Contact and'outerright hand tongue of'a'irelay 42, through thecoil of relay 33 to positive potential. Relay 23 subsequently operates and extends the labove-mentioned circuit to the impulse lunit 21, so that at .thezbeginning of the next step impulse 'transmitted from the impulse unit, relay 33 will be operated. With the switch 29 in its book positionthe operation 'of relay 33 through-its. right hand tongues .extends the circuits from Ythe tongues of the book transmitter H to front contacts of relay 23 `and since relay 23 vis at this time operated, the circuits .are extended through y.the -plug and jack to theimpulse unit 2 and rreperforator lli whereby the :.reperforatoris operated in accordance lwith the Vcode combinationfin the tape 22 `at this time over the pins of book transmitter Il. `:Similarlyfrelay V33 of the other controlcircuits associated with plugged up cord circuits are .operated byfstep impulses vfrom their associated impulse units-.21'flto :effect transmission olf the character in the book transmitter vIl to thecircuitsfto which :their plugs .-Pare .connected. 4the relay33 of ia control-circuit, such vas A, operates, :its .inner left hand vtongue yand front contact completes acircuit for `holding thesame operated through-thefcoil of relay 4|, the back contactand'inner .right hand tongue of relay 42' throughthe front contact and outer left hand tonguefof frelay 39 to ground. The above circuit,

. however, .does `notl eiect-energization ofl relay `ll until-:the end of the steppulser whichv effected operationtoffrelay.: 3-3,.since.the resistance of'theieoil 9g cielayll l :attrust-time` limits the .r'ow of Acurrent in athis: circuit toisonieuvalue below thatjrnecssary to operate relay 541|. YWithirelay 41' operatedaand lockedxup :through the Vlocking circuit `which l.also

` maintains:relay1,33-v operatednthe .next stepfimpulse:` from the..;impulse unity 2,1- ,appearingycnfthe tongue ofA relay I uis. extended through :the front contact:thereof'andr the lcoil of :relay A2 to positive :potentiaLf This, stepiimnulse,v therefore, fet-- iects .energization. of relay ,42 which;y ini fturn,

yopens the'flockingcircuitcf. relays Hand-.33. .Re-

lay. 42 when eoperated. is looked up, vby -af circuit extendingy through :its coil, and. the'front .contact ofits inner leftrhand .tongue to ground 'through by the nrstaandesecondstep pulses from their in'Av dividual. pulsing units to .efectiransmission; 'to all such idle `circuitsof .thezcharacter over .the

sensing .pins :in 'the book .transrnitter; lil.v

Transmitters, esuchfas :l2 and 13,1 vassociated with cord circuitsesuchas D and I-I are disassoclated from their respective cord .circuits by-'fthe .energie zation ofrelaysil'l, the .circuits .tl'ieretosloeiligy completed-.upon the operaticnfof switch .29.I If one. of the jack ,circuits .associated with th cord circuitvoverl which it is desired to transmit .the fbook` Amessageyhappens to.be;busy whenthe plug of. a cord .circuit is-:inserted therein,-` .the seize 'relay 26B of. .such a.;cord l.circuit :iwill lnot gime. mediately operate. However, the cord` :circuit standby larnpfS` will ,be `lightedand remain-.in this condition until :.itslassociatedV relay illifiepel'- ates te' indicate Eto Vthe operator that -the :cord cire; cuit is at .this time vconnected .to an idle. jack-.Keircuit. As described, the standbyilampl 'of each cord circuit that is .plugged up, :islilluminated-'on theplugging operation, and aszsoonzzas-fa lack cir-y cuit is seized, these lamps go out; Accordingly, when the standby lamps St cfallthezplugged up cord circuits go out, the operator .knows that all such cord circuitsare associated at thistirnewith idle sending or jacklcircuits. Concomitantly =with the dperationfof seize relays 2t of they plugged upcord circuits; relays 33 and M .operate and releaseat the vbeginning of the first land secondk step pulses respectively. Relay l2 of each control circuit in the manner described operatesfat the beginning of. the second step pulse and .transmission of the rst character in the book" transmitter to all the sending circuits `is completed when these relays operate. It will be noted that the sequence of operation of relays 39, `33, 4'I ,'and d2 .for each controlcircuit is independent .of each of the other control. circuits since the operation for these relays is. controlled entirely from step pulses derived from impulse units connected :to respective cord circuits. After the above vmentioned relays of each controlv circuit have gone through the described sequence of operation which results in the locking up ofirelays ll2tand .at which time the standby lamps 36 of associated cord circuits will be out, the start button 35 `may be operated.

The operation of start rbutton 35 completes :a circuit through `the coil of .the so-'called .start relay 48, the ylower contactand movable element of `the .start .button :and Ithrough la `series @are asiaeos rangement of make contacts and outer left hand tongues of relays 42 ofeach control circuit or closed contacts 49 of operated cut-out keys 34 to ground at the last control circuit such as H. When a cut-out key 34 is operated, the circuit to its associated control circuit relay 39 is opened at contacts 31 and therefore the associated relays `of such a control circuitwill not go through the described sequence of operation. Either a cut-out switch 34 of each control circuit or its associated relay 42 must be operated whereby the outer left hand tongue shorts contacts 49 of its cut-out key before the start relay 48 can be energized. Hence operation of start button 35 prior to the operation of relays 42 associated with all plugged up cord circuits has no effect on start relay 48. The operation of start relay 4B establishes a locking circuit for itself to ground at the front contacts and the iirst right hand tongues of all operated relays 39. The operated ones of relays 39 are those associated with plugged up cord circuits having energized seize relays 26.

The operation of start relay 48 through its outer tongue and front contact establishes a circuit from potential through the coil of relay 46 to the upper contact of start button 35 so that when the start button is released, the said circuit is extended to ground through contacts 49 of operated cut-out keys 34 or front contacts and tongues of energized relays 42. Operation of relay 46 removes the ground from the locking circuit to all relays 42 whereupon the relays release and restore their associated control circuits to the condition they were in at the reception of the first step impulse. At the time of operation of relay 46, the circuit through the back contact and tongue of relay 44 .parallel to the circuit through the back contact and tongue of relay 46 will be open since relay 44 will normally be operated at the time switch 29 is thrown to its book position. This circuit for operating relay 44 may be traced from positive potential through the coil of relay 44, one of the switch arms of switch 29, thetape lever contacts 32 which are assumed at this time to be closed, and through another switch arm 29 to ground.

On the restoration of the relays of the control circuits to the condition they were in at the time of reception of the first step pulse from the impulse units connected thereto, the sequence of operation. of these relays will be repeated for each pair of succeeding step pulses and concomitantly therewith a character from the book transmitter ii will be transmitted to their assoelated circuits.

When the switch 29 is in its book position, a circuit is completed from negative potential through the step magnet 31 of the book transmitter ll to the front contact of the middle tongue of relay 48. The middle tongue of relay 48 is connected to ground through back stops and tongues of relays 33 and 39 of each controlled circuit in such a manner that the ground is not applied to this tongue of relay 48 unless either one or the other of relays 33 and 39 are deenergized. As will be recalled, relay 39 of each control circuit having its cut-out key unoperated is energized on the plugging up of the associated cord circuit. Hence, the circuit to the step magnet of the book transmitter includes a series circuit through the back contacts and tongues of relay 33 of all operating control circuits. The ground for this circuit is applied at the last control circuit, such as control circuit H of Fig. 3.

i Ween the Start relay 4@ is first operated, relays 8l 33 of operating control circuits will be in deen-f ergized positions and, therefore, operation of relay 48 at this time completes the circuit to the step magnet 3l of book transmitter Il to energize the same. As one of the relays 33 subsequently operates, the circuit to the step magnet 3l will be interrupted and during this time, in the manner set forth, the character over the pins is transmitted to all the connected sending circuits. Some time after the transmission of such a character, all the relays 33 will be deenergized concurrently to complete the circuit to the step magnet 3| for another cycle of operation thereof, Since the relays 33 are all energized at the beginning of step pulses from their individually connected impulse units 21 and deenergized at the beginning of a second impulse, it follows that the step magnet 3| is energized and goes through a cycle of operation once for each pair of step impulses from the impulse units 21. For each operation of step magnet 3|, relays 33 of all connected control circuits have to go through their sequence of operation, and in this manner the stepping of the tape in the ibook transmitter is dependent upon step impulses from all the connected impulse units with certain exceptions hereinafter described.

As described, with the switch 29 in its book position, a circuit is established from ground through the tape lever contacts 32 of the book transmitter and coil of relay 44 to positive potential. l-Ience, when the tape 22 becomes suiiciently taut to open contacts 32, relay 44 is released. It is only the tape lever contacts 32 of the book" transmitter that control the operation of relay 44 and with relay 44 deenergized, a ground is applied through the coils of relays 42 to maintain the same locked up, if in an energized condition, or to lock the same when they do become energized in the manner set forth. With relays 42 locked up, the operation of which occurs at the beginning of the second step pulse of each pair of step impulses, the first step impulse of succeeding pairs will not be extended to associated relays 33, as the circuits thereto will be open at the outer right hand tongues oi relays 42. Hence, with relays 42 in this condition, further transmission from the book transmitter is for the time being halted.

The accumulation of more tape 22 to permit contacts 32 to close, effects energization of relay 44 to remove the ground from the locking circuits to relays 42, whereupon they release and restore associated control circuits to the condition that they respond to succeeding step pulses from associated impulse units to effect transmission of succeeding characters in the tape of book transmitter I l.

As will be noted, the circuit for the step pulse for all cord circuits with the exception of cord circuit A, associated with the "book transmitter, extends through contacts of switch 29 in such a manner that the opening of the tape lever contacts of its associated transmitter has no effect thereon. Accordingly, the transmission through these other cord circuits is independent of the condition of associated tape lever contact such as 32. Furthermore, with the switch 29 .in its book position the circuits to the step magnets of the transmitters of other cord circuits are opened and hence such magnets do not operate.

It sometimes happens that a tape tie-up occurs in the equipment to which the cord circuit is transmitting, such as in the reperforator I4 of a jackv circuit, If such a' condition does Q91,

connectediv 09rd circuit. `The energization of relay 28 normallygperlatestoopen. the` circuit -thfoug-lfrl one; of .the e.coils ofy the; assois continuenigV o the-other connected circuitsun.-

cuit; tofwhich a cordgcircuit suchfa-s D was trans- A mitting, it would completen, circuit ini-the manT nergsuggested ak ,oi/;e,- forltl'iel energization of its cord-jcircuitfrelay,-28. The coil .of relay of control-irciiitp` ,is in v.parallel with that of relay,v 2820i; cord; trcuitpwitnswitch Bain itstbook. positiom `.l'iencerela-y, .'53 ,Willbecome enel;-v gizegd sinfinitalieou slywith thev energization of relayfZf; 'I'herenergltion of relay 38 through its left-handl rig-ue; and front Contact .j shortcir- Cuitscontacts fout, :key 3l. and. then@- fore the circu Jtionoffrelay 46 .will` l thecondition of. the Cut-out ntrol vcircuiti-. 1` Hence, the conf. operate/atten thenenergizationainflthe a'mef-ma' righ fha-p@ to egopensl/ thelcircuit to. its ,associated 1615151369359 that ifurthergstep; .pulses aref'. not effectivefenwt ,central clmllit.-

When ltne enL -fmessagf'a.signalI is .vtransm mitten ythrcugit the fbooi transmitter... I I, the same is effective on all the connected .operating co11d-circuits-iinthemanner pointed,touty in the Blantcnzpatentrito:release Seiterelay tvwlilm in releasing, app a-A groundthroughthe tongues.l and ffrQntcontactsreffrelcys, Wand Zllftozbatteryw. thrpugigga disconnetflam r-l5L- The yoperatoron"` obseryingethe-disoonnect lamps 5 l.. being` muminateci; A vtl'iat tthat-vtransmission of thev fbook message; tQ.ir.11itsf-aSSQQatedMWith-'cord ingillurr fated dis connect lamps 5I, y is Complet l Lemay thet ue011-rem0vethe 55. associated; p1,V Since..transmissicrho .the-

age s halte@througn,a cord circuit, p occurs in .the circuitto which ding, the Seite relayl of,v suclaga; cor@ cu W11-l =fno-t, release -towcause illumination o-its 1 nn ectlainp. .5if.:` There-..- fore, the-,loperetor'fseei gfsomef of fthe-disconnect lamp-stl iilluminatedangl-Qtleer adlsnnetlamps. not iiluminated, knows that the transmission. .of,. ther; b0Qi? messjaege-lrias4 not .been completed thmughfoneaor-fmo. fftlieseotl-iltwits which havef ated dlsconnectilampsf. The opera-to. m then? pmceede-Ltofhave.thecause of. thertre blefcorrectedfand ,the-untransmitted part off. thewbeokiq-mS-Sage sentto Asuch circuits.

It mayvsometim bewdesiroustltoatransmit a fbQek-fl message- 120,1 mberl-Otircuitsi one mere- Ot-Twtchf mae inltheiprcess of ytlm/.ingtrans-- mitte@ the reculert ,an exceptionally.. lqnamessage Whenva cordycircuitfis .plugged l. ulirttc afjack cir- Withers/ inea l-Qliamessage trenrriittedtheroter, '11

geput-If it is desirQusto begin transp; tiesto the.. otherTA ciluitsV W itlioutn Waiting lfworj V suc'lj'r an busy. lack.` ciruit., tope Ome.. iueh 9pereti0;i itsassoietedgwrltlelrz. Cuitrermits. transmission..tothetlieridle- 9911: .lated by @mistige ef the.

It.,. wi11;,be,;fiQtesi .with only theiippcnparti 29m of switch 29 mits@ boelrogsitien., the seieslrl cutsext d' eth1: l .A A tallefcgrourisled n .penleiltlmf www1- of switch 29. Hence,k with` the arrangement'- Circuits ..,Witl1i1.1.. a. glveaifrlteihal'ftlidwith @ath cada. s119111) Vt mi efitothe. Qreuits' indePend-- plurality. .of. .sentii h gntrolncirccuits such asx trolling the operation of said transmitting devices to transmit stored messages, means for disassociating all but one of said control circuits from respective transmitting device and associating the same with the one transmitting device having the non-disassociated control circuit, whereby said one transmitting device is connectable through a plurality of control circuits to a plurality of sending circuits to transmit signals thereover and means dependent upon a busy condition of one or more of said sending circuits toV which said one transmitting device is connected to normally prevent transmission from said one transmitting device to all of said sending circuits.

4. In a telegraph switching system, a plurality oi storage controlled message transmitting devices, anv individual control circuit normally associated with each of said transmitting devices, a plurality of sending circuits, means including said control circuits for normally connecting any one-of said transmitting devices individually to selected ones of said sending circuits and controlling the operation of said transmitting devices to transmit stored messages, means for disassociating in groups all but one of said control circuits from respective transmitting devices and associating the same with the transmitting device having the non-disassociated control circuit, whereby said one transmitting device is connectable through a plurality of control circuits to a plurality oi sending circuits to transmit signals thereover, means to initiate transmission from said one transmitting device to all of the connected sending circuits and means controlled by a busy condition of one or more of said connected sending circuits to prevent operation of said last-mentioned means.

5. In a telegraph message switching system, a plurality of sending circuits, a transmitting device normally operative to transmit messages one at a time to any selected one of said sending circuits` manually operable means to condition said transmitting device to transmit a message ,concurrently to a plurality of said sending circuits, separate selecting means for selecting individual sending circuits for simultaneous transmission thereto of a message from said conditioned transmitting device and timing means individual to the selected sending circuits for determining the respective time of transmission thereto from said transmitting device of the separate code groups of said message.

6. In a telegraph system, a plurality of transmission circuits, a message transmitter for transmitting code groups of signals representing characters of a message, means for transmitting one code group of signals at a time from said transmitter independently to selected ones of said plurality of said transmission circuitsland means individual to each of .said sending circuits for preventing the transmission of a second code group to any one of said circuits until the transmission of the preceding code group to all of the selected circuits.

7. In a telegraph switching system. a plurality of sending circuits, a plurality of transmitting devices, means for normally associating any one of said transmitting devices one at a time with selected ones of said sending circuits, impulse generating means included in said sending circuits to normally initiate ia transmitting device associated therewith into a cycle of operation for each one of a predetermined impulse generated thereby, means for selectively associating a predetermined one of said transmitting devices with a selected plurality of said sending circuits and means dependent upon a predetermined number of impulses from each of said selected plurality of sending circuits with which vsaid predetermined transmitting device is associated to initiate said transmitting device into a cycle of operation.

8. In a telegraph switching system, a plurality of sending circuits, a transmitting device, means for simultaneously associating said transmitting device with selected ones of said sending circuits, impulse generating means included in said sending circuits to normally initiate the transmitting device associated therewith into a cycle of operation for each one of predetermined impulses generated thereby and means for controlling said transmitting device to be initiated into a cycle of operation in response to a plurality of said predetermined impulses from the impulse generating means of the associated circuit.

9. In a telegraph switching system, a plurality of sending circuits, a plurality of transmitting devices, means for normally associating any one of said transmitting devices one at a time with selected ones of said sending circuits, impulse generating means included in said sending circuits to normally initiate a transmitting device associated therewith into a cycle of operation for each one of predetermined impulses generated thereby, means for selectively associating a predetermined one of said transmitting devices with a plurality of said sending circuits, means controlled by a iirst one of said predetermined impulses from a generating means to condition said predetermined transmitting device to transmit a single code group to the associated sending circuit, and means controlled by the following one of said predetermined impulses from the generating means to uncondition said transmitting device i'or transmission to the associated circuit whereby a code group is transmitted to each of the associated sending circuits for each pair of said predetermined impulses from its associated generating means.

10. In a telegraph switching system, a plurality of sending circuits, a plurality of transmitting devices, means for normally associating any one of said transmitting devices one at a time with selected ones of said sending circuits, means for associating a predetermined one of said transmitting devices selectively with a plurality of said sending circuits for transmission thereover of the same message, a signal recording device in each of said sending circuits for recording signals transmitted thereto from a transmitting device, and means controlled by the failure of one or more of the recording devices to record signals transmitted over the associated sending circuit from said predetermined transmitting device to halt further transmission thereto while continuing transmission to the remainder of the circuits associated with said predetermined transmitting device.

ll. In a telegraph switching system, a plurality of sending circuits, a plurality of transmitting devices, means for normally associating any one of said transmitting devices one at a time with selected ones of said sending circuits, means for associating a predetermined one of said transmitting devices selectively with a plurality of said sending circuits for transmission thereover of the same message, a signal recording device in each of saidl sending circuits for recording signals transmitted thereto from a 13 transmitting device, means controlled by the failure of one or more of the recording devices to record signals transmitted over the associated sending circuitffrom said predetermined trans-K,

mitting device to halt further transmission thereto while continuing transmission to the remainder of the circuits associated With said predetermined transmitting device, and means to indicate at the end of a message the circuits to which a complete message has been transmitted.

12.111 a telegraph switching system, a plurality of sending circuits, a plurality of transmitting devices, means for normally associating any one of said transmittingdevices one at a time with selected ones of said sending circuits, means for associating a predetermined one of said transmitting devices selectively with a plurality of said sending circuits for transmission thereover of the same message, a signal recording device in each of said sending circuits for 20 recording signals transmitted thereto from a transmitting device, means controlled bythe failure of one or more of the recording devices to record signals transmitted over the associated sending circuit from said predetermined transmitting device to halt further transmission thereto while continuing transmission to the remainder of the circuits associated with said predetermined transmitting device, indicating kmeans associated with each circuit and means for controlling said indicating means to indicate the circuits having an inoperative recording device associated therewith.

WILLIAM B. BLANTON.

EDWARD J. AGNEW.

REFERENCES CITED The following references are of record in the ile of this patent:

UNITED STATES PATENTS Number Name Date 1,658,516 Daine Feb. 7, 1928 1,749,444 Rae Mar. 4, 1930 1,888,267 Hershey Nov. 22, 1932 2,069,224 Cummings Feb. 2, 1937 2,116,372 Weld May 3, 1938 2,279,295 Blantonl Apr. 14, 1942 2,293,704 Blanton Aug. 25, 1942 2,346,173 Light Apr. 11, 1944 2,365,750 Dore Dec. 26, 1944 2,376,111 Bacon May l5, 1945 

